Connecting to HANA through Studio

Hi Experts:

I shall apologize for this stupid question in advance.

So, we have recently acquired a HANA box (this had HANA rev.23) already installed and set up in it). Now, I have installed the Studio on my laptop, and am trying to connect to HANA.

It gives me two options:

Authentication by Operating System User

Authentication by Database User

Which method should I choose and why? I should point out that I don't have a Database User at this point (is there an administrator user with default password here) . I also don't have a lot of details on what was done previously in this HANA box.

Any help to get me started would be appreciated. Is there a super user that I can use to establish the initial connection?

Imran